Freedom of speech is a basic American right, and university rules against offensive speech do infringe on this right. The problem is now and has always been defining what kind of speech is offensive and should be prohibited. Because people find different things offensive, this is impossible, so freedom of speech was instituted to prevent discrimination and silencing of minorities and activist groups. Universities are important places for discussion and should not limit free speech.
University regulations against offensive speech are necessary to protect students and create a safe learning environment. Hate speech in classrooms or by student groups would harm other students abilities to feel comfortable in their university environment, which would impact their work. Freedom of expression is important, but not at the sacrifice of students' well-being.